The exponential growth of internet traffic and even larger growth projections has precipitated an enormous demand for transmission bandwidth at every level of underlying information infrastructure. In partial response, a 100 Gb/s Ethernet (100 GbE) standard has been recently adopted by the Institute of Electrical and Electronics Engineers (IEEE 802.3ba) and 400 GbE and T Tb/s Ethernet (1 TbE) are currently under study. As may be readily appreciated, terabit optical Ethernet technologies will be affected by the limited bandwidth, high energy consumption and heterogeneity of optical networking infrastructure. To exceed beyond 1 Tb/s serial data rates however, large signal constellation sizes are required for polarization-division multiplexed (PDM) single-carrier quadrature amplitude modulation (QAM) systems with commercially achievable symbol rates. Furthermore, in the context of high-speed optical communications systems, not only the performance of advanced coded modulation schemes but also their complexity is of critical importance.
Given the importance of optical communications systems to contemporary and future communications systems, techniques that enhance their performance would represent a welcome addition to the art.